Acute Glucose Responses Following Arm And Leg Cycling In Pre-diabetics And Type 2 Diabetics

Recent research has shown that a single bout of combined arm and leg cycling (CALC) can improve acute glucose metabolism in non-diabetic college aged adults, but the effects of brief exercise bouts have not been investigated in insulin resistant individuals. We hypothesized that a single 5-min bout of CALC would result in a smaller total area under the curve (tAUC) following an oral glucose tolerance test (OGTT) when compared to no exercise in pre-diabetic and diabetic adults. PURPOSE: To compare acute glucose responses following a short bout of CALC in non-diabetic, pre-diabetic and diabetic adults. METHODS: Diabetes status was based upon a physician diagnosis (pre-diabetics and diabetics). There was also a non-diabetic control group. All participants completed two randomized experimental trials. One trial consisted of a 5-min (5 M) bout of CALC at a self-selected pace. The second trial was a non-exercise control (CON) trial. Immediately following the exercise trial and during the CON trial, participants completed a 60-min oral glucose tolerance test. A 3-factor (gender by diabetes status by trial) repeated measures ANOVA was done to determine if there were significant differences between groups and the change in tAUC values (CON-CALC) during the 60-min OGTT. RESULTS: A total of 51 subjects completed this trial. There were 21 non-diabetics (22.1 ± 3.7 yrs), 14 pre-diabetics (3.9 ± 11.9 yrs), and 16 diabetics (50.3 ± 8.1 yrs). There was a significant interaction between diabetes status and trials for tAUC (p = 0.023). Follow-up analysis showed that for the pre-diabetic group, CALC was signifincatly lower than CON (p < 0.001) with an average mean difference of 208.5 ± 52.8 mg/dl/hr. In the diabetic group, CALC was also significantly lower than CON (p < 0.001) with an average mean difference of186.7 ± 45.0 mg/dl/hr). There was no significant difference between trials for the non-diabetic group. CONCLUSIONS: The results of this study indicate that a 5 min bout of CALC at a self-selected intensity may improve glucose metabolism in pre-diabetics and diabetics. A 5 min bout of CALC does not appear to be sufficient to improve glucose metabolism in non-diabetics.